Average October Temperatures for Illinois

Average temperatures for October at cities throughout Illinois are listed below.

You can jump to a separate table for each region of the state: Chicago Area, Northern Illinois, Central Illinois and Southern Illinois.

The tables give the normal maximum and minimum temperatures based on weather data collected from 1991 to 2020 by the US National Centers for Environmental Information.

Chicago Area

Average October temperatures
High °F	Low °F	Place	High °C	Low °C
63	43	Aurora	17	6
63	43	Chicago Botanical Garden	17	6
64	47	Chicago Midway Airport	18	8
63	45	Chicago O'Hare Airport	17	7
63	41	Elgin	17	5
63	43	Joliet	17	6
62	40	Rochelle	17	4

Northern Illinois

Average temperatures in October
High °F	Low °F	Place	High °C	Low °C
61	42	Antioch	16	6
62	41	DeKalb	17	5
63	42	Dixon	17	6
62	39	Freeport	16	4
65	43	Moline	18	6
62	42	Rockford	17	5
61	43	Waukegan	16	6

Central Illinois

Normal temperatures for October
High °F	Low °F	Place	High °C	Low °C
68	48	Alton	20	9
63	42	Bloomington	17	6
69	46	Cahokia	21	8
66	44	Champaign	19	7
69	46	Charleston	21	8
67	44	Danville	19	7
65	46	Decatur	19	8
65	43	Kankakee	18	6
64	43	Ottawa	18	6
65	44	Peoria	19	7
65	45	Quincy	19	7
67	45	Springfield	20	7

Southern Illinois

Average October temperatures
High °F	Low °F	Place	High °C	Low °C
73	47	Belleville	23	8
71	48	Cairo	22	9
70	44	Carbondale	21	7
68	45	Mt Vernon	20	7

Average Temperatures for Illinois in October

Chicago Area

Northern Illinois

Central Illinois

Southern Illinois

Reference

More Illinois Weather Information